alchi-book: fix patch for htmldiff

src/alchi-book/patches/htmldiff+3e2482bee852bb811f5cc1f2be8f93d6c56ddc0e.patch

@@ -1,4 +1,4 @@
-# generated by patch-package 6.4.7 on 2021-05-12 22:28:59
+# generated by patch-package 6.4.7 on 2021-05-12 22:37:03
 #
 # command:
 #   npx patch-package htmldiff --exclude '^dist/.*'
@@ -10,9 +10,18 @@
 # https://github.com/mblink/htmldiff.js/pull/2
 #
 diff --git a/node_modules/htmldiff/package.json b/node_modules/htmldiff/package.json
-index 9872a13..f5fa0ad 100644
+index 9872a13..578c718 100644
 --- a/node_modules/htmldiff/package.json
 +++ b/node_modules/htmldiff/package.json
+@@ -13,7 +13,7 @@
+   },
+   "private": true,
+   "license": "MIT",
+-  "main": "dist/htmldiff.ts",
++  "main": "dist/htmldiff.js",
+   "files": [
+     "dist/htmldiff.d.ts",
+     "dist/htmldiff.js",
 @@ -22,7 +22,9 @@
    ],
    "type": "module",